The first of 150 giant concrete beams has been lifted into place as work ramps up at a major road junction for the Mersey Gateway Project.

A 550-tonne crane lowered the 106-tonne bridge beam into position at the Bridgewater junction in Runcorn, where the new Astmoor Bridgewater viaduct is being built over the Bridgewater canal. Two elevated slip roads are also being constructed.

This junction will form a key part of the new 9.2km link road, diverting traffic across the new Mersey Gateway Bridge to relieve congestion on the ageing Silver Jubilee Bridge.

Over the coming months, 156 beams, each 40 metres long, will be placed between 24 bridge piers to create the base of the highway for the Astmoor Bridgewater viaduct and the two slip roads.

Pre-cast in Ireland by specialist manufacturer Shay Murtagh, the beams are shipped across the Irish Sea from Dublin to the Liverpool Docks and onwards to Halton by road.

Due to their size and scale, each beam has to be transported on its own special heavy goods vehicle. These vehicles can extend to accommodate abnormal loads, in this case, up to lengths of around 41m.

Deliveries are taking place overnight to minimise traffic disruption. There may be occasional lane closures with traffic stopped for 15 minutes during the night on the Silver Jubilee Bridge to allow the beams to be transported safely across the river. These deliveries will continue until next summer.

Mike Davies, operations manager at construction consortium Merseylink, said: “This is a massive logistical operation as these heavy loads are nearly three times as long as a standard articulated lorry. We’ve done a huge amount of planning to ensure we can get the beams delivered safely to site with minimal disruption to local residents, commuters and businesses.”

A stretch of the westbound Daresbury/Bridgewater Expressway towards the Silver Jubilee Bridge will be closed at Bridgewater until summer 2016 while the beams are installed.

An additional 83 bridge beams, varying in size, will also be installed for road elevations at the Ditton, Widnes Loops and Lodge Lane junctions.

Richard Walker, Merseylink’s project director, said: “Improvements to local highways are a key feature of this project and we are undertaking essential road infrastructure work at a number of major junctions in Halton. When it’s finished, the new link road will provide a seamless route across the new bridge making it easier for people to travel between Runcorn, Widnes and beyond.”

Cllr Rob Polhill, leader of Halton Council and chairman of the Mersey Gateway Crossings Board, said: “This is a hugely exciting moment for the project. Already we can see the pylons for the new bridge emerging from the river and now we will be able to see the brand new road network taking shape. I would encourage everyone to keep an eye on the website gallery and social media to see the rest of the beams make their way through Halton and get lowered into place.”

On the main bridge itself, the hammerheads – the lower part of the pylons – at the north and south pylon are now complete. Construction of the first deck section, known as the ‘pier table’, is due to begin at the south pylon, and the form travellers – the machines that will be used to continue to cast the main bridge deck from the pier table – are being assembled.

The new bridge is scheduled to open in autumn 2017. The Merseylink Consortium was appointed by Halton Council as the project company in 2014, on a 30-year contract to design, build, finance and operate the project. The equity partners are Macquarie Capital Group, BBGI, and FCC Construcción. The construction joint venture is made up of Kier Infrastructure and Overseas, Samsung C&T Corporation and FCC Construcción S.A. Sanef S.A. will deliver and operate the toll system.